Book Review: A Nineteenth-Century Clockmaker, Heinrich Johann Kessels (1781–1849): Ein bedeutender Verfertiger von Chronometern und Präzisionspendeluhren

Abstract

A NINETEENTH-CENTURY CLOCKMAKER Heinrich Johann Kessels (1781-1849): Ein bedeutender Verfertiger von Chronometern und Prazisionspendeluhren. Gunther Oestmann (Acta Historica Astronomiae, xliv; Verlag Harri Deutsch, Frankfurt aM, 2011). Pp. 271. euro24.80. ISBN 978-3-8171-1884-7.Volume xliv of the Acta Historica Astronomiae is dedicated to the life and work of the clockmaker Heinrich Johann Kessels. Gunther Oestmann, author of this work, is a clockmaker and historian of science, whose researches in the field of history of horology, navigation, astronomy, scientific instruments and mathematical geography are well known.The volume is divided into three sections. The first deals with the life and professional achievement of Kessels. He was born in Maastricht, but very little is known of his early years. Certainly he spent some time in England where he learned the art of clock making, working in some of the most renowned workshops of the time. Unfortunately we do not know who his masters were; but he clearly developed a very high level of skill that allowed him to undertake several important works when in 1815 he moved to Paris and entered the shop of the renowned maker, Abraham Louis Breguet. In Paris, Kessels worked on the most sophisticated mechanical timekeepers then being produced, such as marine and pocket chronometers, tourbillons, and highly sophisticated clocks. There he became a highly qualified clockmaker.In Paris Kessels met the German astronomer and geodesist Heinrich Christian Schumacher, one of Breguet's clients. Their relationship played a fundamental role in Kessels's decision to move to northern Germany, first to Hamburg and in 1823 in the nearby Altona, where Schumacher had installed his own astronomical observatory. Kessels established his own workshop there, married in 1829, and became Danish citizen. The time and the conditions for founding a precision clock-making workshop were favourable. In the first half of the nineteenth century, several important astronomical and naval observatories would be founded. Many amateur astronomers were equipping their own private observatories. At the same time, important governmental geodetic surveys were undertaken and the navy as well as the commercial navigation in Denmark and in Northern Germany were fast developing. Altona and Hamburg quickly became important ports. All these activities required an increasing number of scientific instruments, especially box chronometers and astronomical regulators (clocks). Such time-keeping apparatus had to be periodically adjusted. And the Danish King Frederik IV was highly interested in astronomy and related sciences. Schumacher, who had an excellent relationship with the king and the government, could thus facilitate the development of Kessels's business and support his career.Unfortunately, information about Kessels's workshop is scarce. Presumably he had several employees. As general manager of his firm, he supervised the different types of work, personally made or completed the most delicate parts and arranged the final assemblies and tests. …